i dont know, but i wouldnt take a chance not having a reservation. every flight i took was booked solid (all 8 seats), and even had to wait for a next fight this last time. they added an extra flight, saying that we were the 15th flight so far that day (like 3pm). if you book the transfer thru your hotel (which i did) and let them know your flight #, either airline will make sure you get a seat accordingly. remember, they are only 8 or 12 seaters, i think.